GROVE CITY — The Midwestern Intermediate Unit IV board accepted the resignation Wednesday night of its executive director, who the board says had unauthorized credit card charges. The board has ordered a forensic audit of credit card charges made by Cecelia H. Yauger, said Joe Boltz, the Karns City School District representative to the MIU IV, and a member of the board. Yauger had been placed on administrative leave with pay March 27. “Whatever figure I give you is going to be wrong,” Boltz said this morning, declining to share the estimated amount of money involved that the board was told Wednesday from its solicitor, Timothy McNickle, in an executive session. The executive session followed the MIU IV’s annual meeting, which includes the election of 13 board members from 27 school districts in Butler, Lawrence and Mercer counties for three-year terms. Angelo Pezzuolo of New Castle was appointed as interim executive director, during the search for a new one, Boltz said. Pezzuolo was the executive director of the agency from 1992 to 2007, when Yauger was hired. MIU IV is based in Grove City, where Yauger lives. McNickel, who has been investigating Yauger’s credit card use, will contact legal authorities in Mercer County, Boltz said. The MIU IV had no statement this morning. In Butler County, Butler, Karns City, Mars, Moniteau, Seneca Valley, Slippery Rock and South Butler school districts and the Butler Area Vocational-Technical School are covered by the MIU IV.